Indented fiber board



C. G-. MUENCH.

INDENTED FIBER BOARD.

APPLICATION FILED SEPT-29, 1920- l ,417,552.. te ted May 30, 1922.

Smut/bop CARL G. MUENCH, OF ST. PAUL.IliIIII'I IESO'l'A.

mnnn'rnn FIBER 30am).

Specification of Letters Patent. Patented May 30, 1922.

Application filed September 29, 1920. Serial No. 418,549.

To all whom it may 007L0677'L.

Be it known that I, CARL G. MUENCH, a citizen ofthe United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in lndented Fiber Boards; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to indented fiber boards and has for its object to produce a. board which will be more efiicient in use than those heretofore proposed.

With these and other ob'ects in view, the invention consists in the novel article hereinafter disclosed and particularly pointed out in the clainis- Referring to the accompanying drawings forming a part of this specification in which like numerals designate like parts in all the views Figure 1 is a diagrammatic sectional view of a fiber board, illustrating the manner of carrying out the present process;

Fig. 2 is a fragmentary plan view of the finished board;

Fig. 3 is an end elevational view of a portion of the apparatus shown in Fig. 1, and which I is suitable for carrying out the present process;

Fig, 4 is a vertical sectional view taken on the line 44 of Fig. 3; and

Fig. 5 is an enlarged diagrammatic sectional view of a portion of the board shown in Figures 1 and 2, illustrating it in use.

1 indicates a fiber board which is composed of a plurality of classes or sizesof felted cellulose fibers, including the sliver-like fibers 2, of from say 1/ 16 of an inch to 1/8 of an inch wide, and 1/2 inch or more in length; thread-like fibers 3, which may be from 1/32 to 1/64 of an inch in diameter, and from 1/2 to 1 inch or more long; hairlike fibers 4, of from 1/100 to 1/200 of an inch in diameter, and from 1 to 2 inches or more long; and relatively short and very fine fibers 5, such as are ordinarily used in paper making.

Boards ma e as above indicated are very light and porous, due to the sliver-like fibers 2; are relatively strong, due'to the thorough interweaving or entangling of the long thread and hair-like fibers 3 and 14; and have a comparatively smooth or finished git? surface, due to the short, fine fibers 5. 'They are also excellent thermo non-conductors and are therefore especially adapted for use as heat insulating walls or linings for buildings.

When so employed they may be painted d1rectly,. or may be coated with cement, plaster or stucco compositions, with which they bond readily notwithstanding their smooth surface. Under certain circum-' stances, however, it may become desirable to increase the bonding properties, and to this end I propose to indent or slot the surface of the said boardsin the manner which will now be more fully. explained.

Owing to the high degree of porosity of the boards, and further, owing to the several different kinds or classes of fibers used, as above pointed out, it has been. found impractical to produce a clean indentation or slot in the said boards by the use of the ordinary methods and apparatus. Attempts along this line have resulted in exceedingly ragged holes, or in holes wherein the long threadand hair-like fibers were bent and matted down so as to substantially close the pores of the board. It is of course desirable that these said pores be left open as much as possible so that the coating composition such as plaster, stucco,etc., may enter therein and bond therewith. y

I have found, on the other hand, that by employing a cutter such as that illustrated in Figures 1, 3 and 4, revolving at a high rate of speed, a 'relatively clean slot or indentation may be produced in which the pores are not clogged, as above disclosed, but are left open and in condition to permit the ready, entry position therein, thus providin better bondin than would otherwise be t e case.

The said cutter 6 is preferably shaped sub. stantially as shown, and is provided with a plurality of sets of cutting teeth 7 and 8. The teeth 7 are approximately V-shaped in cross section, as shown in Fig. 4, providing the cutting points or apexes 9 and 10. These said points are adapted to make simultaneous incisions atopposite sides of the slot or indentation 11, leaving a substantially pyramidal portion 12 therein, as indicated by the dotted lines in Fig. 1. This said portion l2'however, is removed by the teeth 8, the cutting port-ion of which is substantially straight, as shown in Fig. 4.

The teeth 8, as shown in Fig. 3, alternate around the periphery of the cutter 6 with the teeth 7, so that as soon as the twin incisions are made by the points 9 and 10' of a tooth 7 the pyramidal portion 12 which is left is cut out by the following tooth 8, as will be readily apparent. As above stated, slots or indentations made in this manner are found to be relatively clean cut, the pores of the board being left clear and in condition to receive the Fig. 5.

The cutter 6 may be secured to a revolving spindle 15 in any suitable manner, as by the screw 16, and the said spindle may be driven from any suitable source of power, not shown. I

It is obvious that the indentations 11 may be made of any desired size, and at any angle to the surface of the board 1, but I prefer to make them substantially as shown, so that when the board is in position upon the wall, and the plastic composition 14 is applied thereto, downwardly projecting lugs plastic material, such as 14,

17; will be formed, as shown in Fig 5. This will further increase the efiiciency of the construction, as will be readily apparent.

Vhat I claim is 1. The herein described new article of manufacture comprising a board composed of a plurality of classes of felted cellulose fibers and provided with cleancut indentations, substantially as described.

2. The herein described new article of manufacture comprising a heat insulating plaster board composed of a plurality of classes of felted. cellulose fibers, and provided with a plurality of clean cut plaster bonding indentations cut in one of its surfaces, substantially as described.

In testimony whereof I afiix my signature. in presence of two witnesses.

QARL e. MUENCH. Witnesses a T. B. MUNROE, M. PARQnxrc 

